Effect of No-load and Load Condition on Transformer Sound

2018 ◽  
pp. 11-15
Author(s):  
Dr. Hitesh Paghadar
Keyword(s):  
Experimental Study ◽  
Power Transformer ◽  
Load Condition ◽  
Noise Pollution ◽  
Sound Level ◽  
Measurement Scale ◽  
Dominant Factor ◽  
Public Attention ◽  
Level Measurement ◽  
Human Ear

Increasing environment noise pollution is a matter of great concern and of late has been attracting public attention. Sound produces the minute oscillatory changes in air pressure and is audible to the human ear when in the frequency range of 20Hz to 20 kHz. The chief sources of audible sound are the magnetic circuit of transformer which produces sound due to magnetostriction phenomenon, vibration of windings, tank and other structural parts, and the noise produced by cooling equipments. This paper presents the validation for sound level measurement scale, why A-weighted scale is accepted for sound level measurement, experimental study carried out on 10MVA Power Transformer. Also presents the outcomes of comparison between No-Load sound & Load sound level measurement, experimental study carried out on different transformer like - 10MVA, 50MVA, 100MVA Power Transformer, to define the dominant factor of transformer sound generation.

scholarly journals Evaluating of Noise Pollution in the Airside of Imam Khomeini International Airport

2017 ◽  
Vol 11 (6) ◽  
pp. 47
Author(s):  
Shabani Sh. ◽  
Zarei Sh.
Keyword(s):  
Sound Pressure ◽  
Noise Pollution ◽  
Sound Level ◽  
Environmental Standards ◽  
Analysis Method ◽  
Measurement Evaluation ◽  
International Airport ◽  
Level Measurement ◽  
Management Principle ◽  
Level Meter

Detection, measurement and monitoring of environmental pollution are considered as one of the decision basics in the environmental management. Principle planning for solving environmental problems is not possible without reliance to assured measurement with the help of new and powerful systems in monitoring. In this regard the noise pollution of airports is of great importance. In this paper by using device analysis method and utilizing a calibrated sound level meter device, sources of noise pollution recognition, noise and sound pressure level measurement, evaluation and comparison of them with environmental standards, and airside control actions of the Imam Khomeini international airport have been performed and it was showed, that the runway, ground safety and the dock have been respectively the main pollutants, so that noise pollution in the Apron area and runway at night have been 80.7% more than Iran standards and the ground safety site while alarm broadcasting has been 53.1% at daytime and 61.1% at night more than standards and these values for Dock has been 20.88% and also the value of noise pollutants in water refinery sites, watchtower, taxi parking and pilgrim terminals have met standards. Finally some solutions against noise pollution have been proposed.

Noise Pollution: Neonatal Aspects

PEDIATRICS ◽  
1974 ◽  
Vol 54 (4) ◽  
pp. 476-479
Author(s):  
Robert W. Miller ◽  
William B. Brendel ◽  
Robert L. Brent ◽  
J. Julian Chisolm ◽  
John L. Doyle ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Rock Music ◽  
Low Frequency ◽  
Noise Pollution ◽  
Sound Level ◽  
Low Frequencies ◽  
Ototoxic Drugs ◽  
Human Ear ◽  
Hospital Noise ◽  
Ototoxic Drug

The deafening effect of high intensity noise is well known—from rock music, aircraft, snowmobiles, motorcycles and the shooting of guns. The effects of hospital noise and its interaction with ototoxic drugs are less well known. The subject is of particular importance to pediatricians, because infants in incubators are exposed to substantial noise from the motor, airflow, respirators, slamming of incubator doors and the baby's own crying. Furthermore, animal experimentation1 shows that the ototoxic drug, kanamycin (often given to the premature infant to combat sepsis), can potentiate the effect of noise on hearing loss as much as 100-fold. Whether or not an interaction between noise and potentially ototoxic drugs occurs in man is as yet unknown. MEASUREMENT Noise has frequency and intensity. Frequency is measured in cycles per second, designated hertz (Hz). The young human ear is sensitive to a frequency range of 20 to 20,000 Hz. White noise, the auditory counterpart of white light, has equal energy in each frequency in the audible range. Intensity is measured in decibels on a scale which is linear with respect to audible frequencies. This measurement is designated dB (linear). Since the human ear is more sensitive to the damaging effects of high frequency sound than to low frequency, a better correlate with noise-induced hearing loss can be obtained when low frequencies are filtered out. Filtered sound level, measured on a so-called A-weighted scale, is designated dB(A). Room conversation produces 60 to 70 dB(A), rock music 100 to 120 dB(A) and snowmobiles 105 to 135 dB(A) for the driver.

Testing of Sonic-Absorbent Panels’ Behavior in Open-Air Environment

2012 ◽  
Author(s):  
Petru A. Pop ◽  
Patricia A. Ungur ◽  
Liviu Lazar ◽  
Mircea Gordan ◽  
Florin M. Marcu
Keyword(s):  
High Frequency ◽  
Noise Pollution ◽  
Sound Level ◽  
Sound Level Meter ◽  
Data Logger ◽  
Public Buildings ◽  
Gypsum Plaster ◽  
Level Meter ◽  
And Control

One wildly used method to reduce and control the noise pollution in green city’s buildings is using sonic-absorbent panels. Their applications can be multiple, such as the insulation of buildings, acoustic barriers and fences along the highway or in front of supermarkets, hospitals and other public buildings. This paper presents a method for testing the behavior of sonic-absorbent panels in open-air environment. The work represents a carrying on of previous research about absorbent materials from gypsum family, tested in lab conditions. The experiment setup used a dynamic installation and as a sample a stand formed by six sonic-absorbent panels from special modeling alpha-gypsum plaster. This installation has been composed of two loudspeakers for emitting the sound at a well-defined frequency by the first laptop, the microphone for detecting and transmitting the signal to the second laptop for analyzing and processing the data. All operations were performed using MATLAB Programs, while a Data Logger Sound Level Meter type CENTER 332 was put on near the microphone to compare both results. The first experiment of acoustic stand has been realized by setting up the installation at a frequency from 50 Hz to 1250 Hz and altering the distance between loudspeakers and stand at 0.5m to 1m and 1.5m, respectively. The second experiment kept the same test’s conditions, while two and three layers of sonic-absorbent panels formed the stand, respectively, but at same distance from source of 0.5 m. In both tests, the results underlined the good sonic-absorbent properties of these panels, especially at medium and high frequency, which can recommend using the panels for multiple outside applications.

scholarly journals Experimental Study of Pipes Shape Effect on Noise Reduction

2017 ◽  
Vol 5 (1) ◽  
pp. 71-86
Author(s):  
Muna S. Kassim ◽  
Ammar Fadhil Hussein Al-Maliki
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Noise Reduction ◽  
Power Plants ◽  
Combustion Engine ◽  
Exhaust System ◽  
Noise Pollution ◽  
Shape Effect ◽  
Pipe Length ◽  
Exhaust Noise

Internal combustion engine is a major source of noise pollution. These engines are used for various purposes such as, in power plants, automobiles, locomotives, and in various manufacturing machineries. The noise is caused by two reasons; the first reason is the pulses which created when the burst of high pressure gas suddenly enters the exhaust system, while the second reason is the friction of various parts of the engine where the exhaust noise is the most dominant. The limitation of the noise caused by the exhaust system is accomplished by the use of silencers and mufflers. The aim of this study is the reduction of the noise by changing its inlet and outlet pipe length and shape. Also the losses in noise for different length and shapes have been investigated experimentally. The results show that the corrugated pipe is preferable for noise reduction.

scholarly journals Status of noise pollution in urban area of Dharan Sub- Metropolitan City and Inaruwa Municipality of Sunsari District, Nepal

2017 ◽  
Vol 7 (1) ◽  
pp. 35-40
Author(s):  
Ranij Shrestha ◽  
Alankar Kafle ◽  
Kul Prasad Limbu
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pollution Assessment ◽  
Noise Pollution ◽  
Pressure Level ◽  
Noise Levels ◽  
Night Time ◽  
Level Measurement ◽  
Standard Value ◽  
Autumn And Winter

The environmental noise level measurement in Dharan and Inaruwa cities of eastern Nepal were conducted and compared with the ambient noise standards provided by Government of Nepal. The noise pollution assessment was performed in autumn and winter seasons by the indicator average day time sound pressure level (Ld, during 7.00 to 22.00 hrs) and average night time sound pressure level (Ln, during 22.00 to 7.00 hrs). The Ld and Ln values at the commercial, silence and residential zones of Dharan were 78 to 82 and 72 to 73, 65 to 73 and 60 to 70, 65 to 76 and 62 to 64 dB(A) in autumn and 78 to 79 and 72 to 76, 64 to 71 and 58 to 68, 63 to 74 and 60 to 62 dB(A) in winter, respectively whereas for Inaruwa, measurement were 75 to 77 and 73 to 75, 59 and 57, 67 and 60 dB(A) in autumn and 66 to 70 and 63 to 68, 55 and 53, 65 and 58 dB(A) in winter, respectively. The results showed that noise levels exceeded the standard value at most of the sites.

scholarly journals Investigation of Noise Pollution Distribution in Different Parts of Yazd Textile Factories

2021 ◽  
Author(s):  
Mohammad Javad Zare Sakhvidi ◽  
Hamideh Bidel ◽  
Ahmad Ali Kheirandish
Keyword(s):  
Occupational Exposure ◽  
Sound Pressure Level ◽  
Textile Industry ◽  
Sound Pressure ◽  
Noise Pollution ◽  
Sound Level ◽  
Pressure Level ◽  
Cross Sectional ◽  
Sound Pressure Levels ◽  
Different Parts

 Background: Chronic occupational exposure to noise is an unavoidable reality in the country's textile industry and even other countries. The aim of this study was to compare the sound pressure level in different parts of the textile industry in Yazd and in different parts of the textile industry. Methods: This cross-sectional study was performed on 930 textile workers in Yazd. A questionnaire was used to obtain demographic information and how to use protective equipment. Then, to obtain the sound pressure level of each unit and device and to use the measurement principles, a calibrated sound level meter was used. Then the results were analyzed using SPSS Ver.29 software. Results: The participants in this study were 714 males and 216 females with a mean age of 35.27 and 33.63 years, respectively. Seven hundred fifty-six participants (81.29%) were exposed to sound pressure levels higher than 85 dB. Among the participants, only 18.39% of the people used a protective phone permanently. Except for factory E, with an average sound pressure level of 77.78 dB, the rest of the factories had an average sound pressure level higher than the occupational exposure limit. The sound measurement results of different devices show that the sound pressure levels above 90 dB are related to the parts of Dolatab, Ring, Kinetting (knitting), Chanel, Autoconer, Dolakni, Open End, MultiLakni, Tabandegi, Texture, and Poy. Conclusion: Based on the results of the present study, noise above 90 dB is considered as one of the main risk factors in most parts of the textile industry (spinning and weaving), which in the absence of engineering, managerial or individual controls on it causes hearing loss in becoming employees of this industry

scholarly journals Impacts of vehicle tire on slip resistance and sound pollution in asphalt pavements

2021 ◽  
Vol 2 (3) ◽  
pp. 16-21
Author(s):  
Saeed Abbassi
Keyword(s):  
Urban Areas ◽  
Noise Pollution ◽  
Sound Level ◽  
Asphalt Pavements ◽  
Fine Grained ◽  
Sensitive Areas ◽  
Slip Resistance ◽  
Materials Used ◽  
The Cost ◽  
Pavement Friction

Noise pollution caused by vehicle traffic is one of the major problems in urban areas with road expansion. Due to the increase in the cost of construction and installation of sound walls to deal with noise pollution, to deal with this problem should look for methods that do not have additional costs and operating costs. Improving the pavement texture is one of the most effective ways to reduce tire noise and pavement and reduce the asphalt surface’s sound. To evaluate the slip resistance of asphalt, the English pendulum test according to ASTM E303-74 standard was performed on wet parts of asphalt in wet conditions. This device is used to examine the fine texture of the pavement. The number of pavement friction with a negative coefficient of 0.1469 has an inverse ratio with the intensity of sound level increases the number of pavement friction aligned with the amount of sound level created decreases. On the other hand, the depth of pavement texture, which is determined as the size of pavement materials, with a coefficient of 0.2810, has a direct ratio with the amount of noise pollution, and the smaller the number of fine-grained materials used will increase the sound level. According to the results of the coefficients estimated from the equation, it can be concluded that the preparation of pavements with an amount of friction can reduce the amount of noise pollution emitted by the movement of vehicles, especially in urban areas and sensitive areas. Therefore, it is recommended that in acoustically sensitive areas, in preparing pavements, arrangements be made to use coarser materials and maintain proper pavement resistance. For this purpose, in this article, the pavement’s texture is examined in the amount of noise created due to the tire’s interaction and the pavement.

scholarly journals Assessments and Control of Anthropogenic Noise Pollution in Students’ Residential Areas in Ogbomoso

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. O. Ajayeoba
Keyword(s):  
Medical History ◽  
Undergraduate Students ◽  
Circuit Breaker ◽  
Noise Pollution ◽  
Sound Level ◽  
Anthropogenic Sources ◽  
Anthropogenic Noise ◽  
Residential Areas ◽  
Sound System ◽  
And Control

Increased rate of noise-associated risk factors such as speech interference and reduction in productivity, necessitated that control and regulation measures be put in place, to contain anthropogenic noise pollution in the students’ hostels. Therefore, this study assessed the various anthropogenic sources of noise pollution in students’ hostels and developed a Sound Level Monitor and Control (SLMC) device. 1250 undergraduate students across 5 students’ residential zones were sampled for demographics and investigations were conducted into respondents’ perceived medical history, identification of noise sources, and evaluation of hearing loss. Effects of noise levels were evaluated using 100 respondents’ rooms per zone following standard procedures, considering Sound-System-Only (SSO), Generators-Only (GO), and combination of Sound-System-and-Generator (SSG), loud-conversations, etc., as sources of noise. However, a noise control device incorporated with a circuit breaker was developed. The respondents were 51.2% male and 48.8% female, with 58% in the age range 18 – 27 years. The medical history showed that 1.2 and 6.4% had a hearing problem in short and long times, respectively, while 43.6% affirmed that SSO was a major noise pollution causal factor. SSO, GO, loud conversations, traffic, and grinding machines were identified as the prominent sources of anthropogenic induced noise. The minimum average SL result gave a value of 62.8400dB for both ventilated and unventilated rooms, which is 14% above 55dB threshold value recommended by the National Environmental Standards and Regulations Enforcement Agency. The developed SLMC device gave notification at the SL above 55dB for 15 seconds before disconnecting the sound system if not regulated.

Four Wheeler’s Health Monitoring by Sound Level Measurement: A Case Study

2021 ◽  
pp. 93-101
Author(s):  
Manpreet Singh ◽  
Simran Singh ◽  
Rajeev Kumar ◽  
Sumit Shoor ◽  
Piyush Gulati ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Sound Level ◽  
Level Measurement
Sign in / Sign up

Export Citation Format

Share Document